Biostereometric analysis of the tympanic membrane using photogrammetric techniques will use objective and precise engineering techniques to document important clinical observations which were previously made casually and subjectively. The technology to be used has been extensively developed for commercial, military and space applications. It provides three-dimensional contour maps, volumes, cross-sectional contours, etc. Fine India ink spray will be applied to the tympanic membrane of both animal and human subjects. Stereophotographs will be obtained and using optical scanning, information theory, and three-dimensional graphics, the following parameters will be examined: (1) the definition and documentation of curvature and volume displacement of the tympanic membrane in normal and diseased human ears; (2) assessment of the contribution of the tympanic membrane to the transformer ratio of the ear according to the Helmholtz-Tonndorf Theory based on the curved lever principle; (3) documentation of change of shape during chronic eustachian tube dysfunction and negative middle ear pressure, with evaluation of the hysteresis of the elastic properties of the tympanic membrane; (4) evaluation of changes in migration pattern of squamous epithelium along the tympanic membrane in normal and diseased ears in both humans and animals.